A beverage delivery system may include a source of beverage such as a keg of beer, which maintains the beer under pressure by carbon dioxide. Conduits and coils generally carries the beer from the keg to a discharge device such as a manually operated spigot.
Beer in kegs are often stored at relatively low temperatures in refrigerated areas. In taverns where the beer is served to customers conduits or pipes are used to connect the kegs to the spigots in the customer areas. Changes in pressures and temperatures while the beer is ready for dispensing tends to change the taste and aroma of beer and special care generally is taken to avoid these changes.
Beverage delivery systems involving beer and other beverages must be maintained as clean as possible to comply with health standards. In many cases, state laws have been enacted requiring coils and the connecting conduits or pipes to be periodically cleaned. One reason for the strict sanitation requirement in connection with beer delivery systems is that some of the materials in beer may chemically react to cause particle precipitations in the delivery conduits, which tend to affect the taste of the beer and possibly lead to health problems.
Beverage cleaning systems have been disclosed in Jones U.S. Pat. No. 1,993,371; Warcup U.S. Pat. No. 2,458,230; Audia U.S. Pat. No. 2,645,379; Hilts U.S. Pat. No. 3,036,741; Mirabile U.S. Pat. Nos. 4,527,585,and 4,572,230 and Doak U.S. Pat. No. 4,582,226.
In some of these patents cleaning means are disclosed to clean the delivery conduits and other parts of a beverage delivery system.
In some of these patents the normal beer delivery is discontinued during the cleaning operation. In some such cleaning systems, chemical powders have been mixed with water to form a cleaning solution which is forced through conduits and other devices to perform a cleaning operation when the delivery system is shut down. For example, Warcup U.S. Pat. 2,563,385 uses apparatus for controlling the concentration of a chemical cleaning fluid in water. An operator pushes a control valve to supply the chemical cleaning fluid to the water line.
The Audia U.S. Pat. No. 2,645,379 uses a gravity flow valve to control the amount a cleaner solution which is added to water in a tank.
Mirabile U.S. Pat. No. 4,527,585 discloses hot water under pressure siphoning cleaning solution from a reservoir. A pump is operated to cause vacuum in the conduits. The vacuum caused by the pump, together with the pressure of the incoming hot water, causes turbulance which carries the cleaning solution into the conduits.
Chemical solutions have been mixed with pressurized water flowing from a conventional source to clean conduits, as illustrated in the U.S. Pat. No. 4,527,385.
Generally, a chemical solution used for cleaning comprises a mixture of water and a chemical powder which is dispensed in the main water supply flowing through the cleaning system. The concentration or amount of the chemical powder mixed with water is dependent upon the particular system involved. For example, different concentrations of the chemical powder are generally required for different systems, with the concentrations being determined by the size of the dispensing system involved, the number of conduits to be cleaned, the length of time allotted to the cleaning operations and other factors.
Different dispensing systems generally produce different back pressures when different numbers and lengths of conduits are involved. These different back pressures effect the pressure of the main flow of water used in the cleaning system. To compensate for different back pressures, the concentration of the chemical mixed with the water in the cleaning solution may require changes. The present invention relates to this problem and is directed towards providing a relatively simple automatic cleaning system which may be easily attached to different dispensing systems involving different back pressures resulting from different number or sizes or the conduits in a system.
The systems described in the cited patents have generally been designed to accommodate a particular type of beverage delivery system and are not readily adaptable to accommodate different systems involving different number of beverage sources, conduits and spigots. Major structural changes in the cleaning equipment would generally be required when changes in the delivery systems are involved. This is primarily caused by different numbers of conduits resulting in different back pressures in the water passing to the conduits when the water source of pressure is constant.
Some of the patents mentioned above involving the use of cleaning fluids do not have the versatility necessary to accommodate different systems without resorting to major structural changes in the delivery system.
The present invention is directed to providing a simple, inexpensive system with a minimum number of parts, which does not require changes in any of the mechanical parts when different delivery systems are involved. This is accomplished by measuring the water pressure levels at the point that the water enters the delivery conduits during a cleaning operation and determining the chemical concentration of the cleaning solution used to give maximum cleaning while still economizing on the amount of the chemical in the cleaning solution. The cleaning system is adaptable to vastly different delivery systems with no changes being required in either the delivery or cleaning systems after the initial installation.